In his speech, X argued that African Americans could not wait for white Americans to offer them equality.

"No, we’re not anti-white … but we don't have time for the white man. The white man is on top already, the white man is the boss already. The white man has economic security already, he has first-class citizenship already, so you're wasting your time talking to the white man. We are working on our people," he said.

Still, he spoke in a professorial tone, in contrast to the more aggressive style that characterized his other speeches of that era.

"I am thankful to Allah for those of you who are here this evening, because to me it shows that you have an open mind, and I don't think you came here for me to convert you into being a Muslim, or do I think that you think I came here for you to convert me back into being a Christian," he said. "When Eisenhower and Khrushchev sat down an spoke to each other, they weren't there to convert each other. But their intelligence caused them to recognize the times, the conditions and the importance of each other's position."

The audio was discovered by a 22-year-old student, coincidentally named Malcolm Burnley. He was going through an old student newspaper, saw a mention of Malcolm X on campus and found the audio gathering dust in the university's archives. The speech is credited with exposing white students to a different side of black America.

"The Takeaway," a joint production of WNYC and Public Radio International in collaboration with WGBH, aired excerpts on Feb. 7. Hear more, including comments from Burnley, at thetakeaway.org.